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1.
Ann Ig ; 35(2): 136-148, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35603971

RESUMO

Aim: To explore the reasons for Italian midwives' decision to migrate, and their lived professional and emotional experiences. Methods: A descriptive phenomenological study was conducted recruiting Italian midwives who were working abroad in European countries. We offered a telephone or web interview. Two researchers conducted, audio-recorded, and fully transcribed the interviews and other two researchers, independently, performed a content analysis. Results: Thirty-two midwives having professional experiences in the UK, Ireland, Germany, Switzerland, and Spain were interviewed. Five themes emerged: 1) Education, 2) Migration decision-making, 3) Professional experience abroad, 4) Midwives' perceptions of their role, 5) Satisfaction versus desire to return. Our findings show a general dissatisfaction with Italian job opportunities in terms both of access to employment and work conditions. This scenario is complicated by the status of the professional midwifery in Italy. Conclusion: Stakeholders should ensure that the migration of Italian midwives is not synonymous with dispersion but is a channel of professional growth and mutual exchange.


Assuntos
Tocologia , Enfermeiros Obstétricos , Gravidez , Humanos , Feminino , Enfermeiros Obstétricos/psicologia , Pesquisa Qualitativa , Europa (Continente) , Itália
2.
Med Oral Patol Oral Cir Bucal ; 25(2): e277-e282, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31967979

RESUMO

BACKGROUND: To assess if photobiostimulation (PBS) alleviates pain intensity/duration and swelling after implant surgery. MATERIAL AND METHODS: Sixty subjects (27 male and 33 female, with a mean age of 47,13 8.05 years) were included and randomly assigned to experimental group (implant surgery and photobiostimulation), placebo group (implant surgery and simulated photobiostimulation) and control group (implant surgery only). INCLUSION CRITERIA: subjects older than 20 years, with a healthy oral mucosa and requiring implant surgery. EXCLUSION CRITERIA: pregnancy, history of implant failure, light sensitivity, metabolic deseases, consumption of antibiotics or corticosteroids in the last two weeks, smokers and alcohol drinkers. Patients reported the pain experienced by using a numeric rating scale (NRS) at 2 hours, 6 hours, 12 hours, 24 hours and from day 2 to 7. Swelling score was assessed by linear measurements and type and number of analgesic drugs within each time-point were recorded on a spreadsheet. Data of pain and amount of swelling were compared among the three groups by using the Kruskal-Wallis H Test and post-hoc comparisons tests. RESULTS: Pain in the experimental group was less compared to controls and placebo group, at each time intervals (p < 0.001) as well as the maximum pain score (experimental group: median = 2, interquartile range 2-3; control group: median = 8, interquartile range 3,75-9; placebo group: median = 8, interquartile range 6,25-9). Swelling was almost insignificant in the experimental group (maximum value = 1, interquartile range 0-2,75, at 24 hours) compared with control (maximum value = 6, interquartile range 5-8,75, at 24 hours) and placebo (maximum value = 6, interquartile range 5-8, at 24 hours). Subjects in the experimental group assumed less analgesics compared to both controls and placebo groups. CONCLUSIONS: Photobiostimulation is an effective method to reduce pain intensity/duration and swelling after implant surgery.


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Bucais , Idoso de 80 Anos ou mais , Analgésicos , Método Duplo-Cego , Feminino , Humanos , Masculino , Dor Pós-Operatória
3.
Med Oral Patol Oral Cir Bucal ; 24(4): e473-e482, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31232392

RESUMO

BACKGROUND: The purpose was to identify and assess the existing scientific evidence from epidemiologic, non-experimental, observational studies of associations between Marfan's syndrome and oral diseases. MATERIAL AND METHODS: Electronic literature searches in MEDLINE (OVID), The Cochrane Library, Scopus and the Web of Science were conducted to identify all relevant articles. Eligibility was based on inclusion criteria, and quality assessments were conducted. The outcome variables were probing depth, gingival margin, clinical attachment level, bleeding on probing, gingival status, periodontal status, tooth mobility, furcation involvement and decayed, missing and filled teeth index. After extracting data, meta-analyses were carried out. RESULTS: Out of 527 potentially eligible papers, 3 cross-sectional studies were included. No statistically significant differences were found in the number of sites with bleeding on probing (OR: 1.26; 95% CI: 0.47 to 3.42; P = 0.65; I2: 0%), probing depth (MD: -0.14 mm; 95% CI: -0.24 to 0.53; P = 0.46; I2: 93%), periodontal status (WMD: 0.68 points; 95% CI: -0.48 to 1.83; P = 0.25; I2: 98%) nor number of decayed, missing and filled teeth index score (MD: 1.08 points.; 95% CI: -1.27 to 3.42; P = 0.37; I2: 0%). CONCLUSIONS: Patients diagnosed with Marfan's syndrome do not seem to have worsened oral health status. Due to the high number of patients with Marfan's syndrome that have prosthetic heart valves, an adequate dental monitoring as well as a strict maintenance therapy program should be implemented.


Assuntos
Síndrome de Marfan , Saúde Bucal , Estudos Transversais , Humanos
4.
Med Oral Patol Oral Cir Bucal ; 22(4): e417-e424, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28578372

RESUMO

BACKGROUND: Obstructive sleep apnoea (OSA) is a common disorder that may affect at least 2 to 4% of the adult population. Nasal-Continuous Positive Airway Pressure (N-CPAP) is today considered the gold standard for the treatment of OSA. The development of oral appliances (OAs) represents a new approach for the management of this pathology. The aim of this systematic review is to compare the efficacy of OAs and N-CPAP in the treatment of patients with mild to severe OSA. MATERIAL AND METHODS: A PubMed-MEDLINE and Cochrane databases search of articles published between 1982 and 2016 comparing the effect of N-CPAP and OAs in OSA patients was conducted during July 2016. The studies were selected and stratified according to PRISMA and SORT criteria. The main outcome measure was post-treatment Apnoea-Hypopnoea Index (AHI) while secondary outcomes included post-treatment Epworth Score Scale (ESS) score and lowest Oxygen Saturation level. RESULTS: N-CPAP was significantly more effective in suppressing AHI than OA. Moreover, N- CPAP was significantly more effective in increasing post-treatment lowest Oxygen Saturation level than OA. However, no significant different in decreasing ESS values was found between the two treatments. CONCLUSIONS: On the basis of evidence in this review it would appear appropriate to offer OA therapy to those who are unwilling or unable to persist with CPAP therapy. N-CPAP still must be considered the gold standard treatment for OSA and, therefore, OAs may be included in the list of alternative options.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Avanço Mandibular/instrumentação , Apneia Obstrutiva do Sono/terapia , Humanos , Índice de Gravidade de Doença
5.
Cereb Cortex ; 25(6): 1654-67, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24421176

RESUMO

During foveal reaching, the activity of neurons in the macaque medial posterior parietal area V6A is modulated by both gaze and arm direction. In the present work, we dissociated the position of gaze and reaching targets, and studied the neural activity of single V6A cells while the eyes and reaching targets were arranged in different spatial configurations (peripheral and foveal combinations). Target position influenced neural activity in all stages of the task, from visual presentation of target and movement planning, through reach execution and holding time. The majority of neurons preferred reaches directed toward peripheral targets, rather than foveal. Most neurons discharged in both premovement and action epochs. In most cases, reaching activity was tuned coherently across action planning and execution. When reaches were planned and executed in different eye/target configurations, multiple analyses revealed that few neurons coded reaching actions according to the absolute position of target, or to the position of target relative to the eye. The majority of cells responded to a combination of both these factors. These data suggest that V6A contains multiple representations of spatial information for reaching, consistent with a role of this area in forming cross-reference frame representations to be used by premotor cortex.


Assuntos
Movimento/fisiologia , Neurônios/fisiologia , Lobo Parietal/citologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Potenciais de Ação/fisiologia , Análise de Variância , Animais , Atenção , Feminino , Fixação Ocular/fisiologia , Macaca fascicularis , Masculino , Fatores de Tempo
6.
Cereb Cortex ; 24(12): 3209-20, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23853212

RESUMO

The frames of reference used by neurons in posterior parietal cortex (PPC) to encode spatial locations during arm reaching movements is a debated topic in modern neurophysiology. Traditionally, target location, encoded in retinocentric reference frame (RF) in caudal PPC, was assumed to be serially transformed to body-centered and then hand-centered coordinates rostrally. However, recent studies suggest that these transformations occur within a single area. The caudal PPC area V6A has been shown to represent reach targets in eye-centered, body-centered, and a combination of both RFs, but the presence of hand-centered coding has not been yet investigated. To examine this issue, 141 single neurons were recorded from V6A in 2 Macaca fascicularis monkeys while they performed a foveated reaching task in darkness. The targets were presented at different distances and lateralities from the body and were reached from initial hand positions located at different depths. Most V6A cells used body-centered, or mixed body- and hand-centered coordinates. Only a few neurons used pure hand-centered coordinates, thus clearly distinguishing V6A from nearby PPC regions. Our findings support the view of a gradual RF transformation in PPC and also highlight the impact of mixed frames of reference.


Assuntos
Potenciais de Ação/fisiologia , Mãos/fisiologia , Neurônios/fisiologia , Lobo Parietal/citologia , Lobo Parietal/fisiologia , Percepção Espacial/fisiologia , Análise de Variância , Animais , Braço/fisiologia , Movimentos Oculares/fisiologia , Lateralidade Funcional , Macaca fascicularis , Masculino , Movimento , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Fatores de Tempo
7.
Cereb Cortex ; 24(6): 1645-57, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23382514

RESUMO

Many psychophysical studies suggest that target depth and direction during reaches are processed independently, but the neurophysiological support to this view is so far limited. Here, we investigated the representation of reach depth and direction by single neurons in area V6A of the medial posterior parietal cortex (PPC) of macaques, while a fixation-to-reach task in 3-dimensional (3D) space was performed. We found that, in a substantial percentage of V6A neurons, depth and direction signals jointly influenced fixation, planning, and arm movement-related activity. While target depth and direction were equally encoded during fixation, depth tuning became stronger during arm movement planning, execution, and target holding. The spatial tuning of fixation activity was often maintained across epochs, and depth tuning persisted more than directional tuning across epochs. These findings support for the first time the existence of a common neural substrate for the encoding of target depth and direction during reaches in the PPC. Present results also highlight the presence of several types of V6A cells that process independently or jointly signals about eye position and arm movement planning and execution in order to control reaches in 3D space. A conceptual framework for the processing of depth and direction for reaching is proposed.


Assuntos
Braço/fisiologia , Percepção de Profundidade/fisiologia , Neurônios/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Potenciais de Ação , Animais , Função Executiva/fisiologia , Movimentos Oculares/fisiologia , Fixação Ocular/fisiologia , Macaca fascicularis , Masculino , Microeletrodos , Modelos Neurológicos , Testes Neuropsicológicos , Lobo Parietal/anatomia & histologia
8.
Neuroimage ; 82: 517-30, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23770406

RESUMO

In macaque monkeys, V6A is a visuomotor area located in the anterior bank of the POs, dorsal and anterior to retinotopically-organized extrastriate area V6 (Galletti et al., 1996). Unlike V6, V6A represents both contra- and ipsilateral visual fields and is broadly retinotopically organized (Galletti et al., 1999b). The contralateral lower visual field is over-represented in V6A. The central 20°-30° of the visual field is mainly represented dorsally (V6Ad) and the periphery ventrally (V6Av), at the border with V6. Both sectors of area V6A contain arm movement-related cells, active during spatially-directed reaching movements (Gamberini et al., 2011). In humans, we previously mapped the retinotopic organization of area V6 (Pitzalis et al., 2006). Here, using phase-encoded fMRI, cortical surface-based analysis and wide-field retinotopic mapping, we define a new cortical region that borders V6 anteriorly and shows a clear over-representation of the contralateral lower visual field and the periphery. As with macaque V6A, the eccentricity increases moving ventrally within the area. The new region contains a non-mirror-image representation of the visual field. Functional mapping reveals that, as in macaque V6A, the new region, but not the nearby area V6, responds during finger pointing and reaching movements. Based on similarity in position, retinotopic properties, functional organization and relationship with the neighboring extrastriate visual areas, we propose that the new cortical region is the human homologue of macaque area V6A.


Assuntos
Mapeamento Encefálico , Córtex Visual/anatomia & histologia , Adulto , Animais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Macaca , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Vias Visuais/anatomia & histologia
9.
Cereb Cortex ; 20(2): 411-24, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19502476

RESUMO

Cortical-surface-based functional Magnetic Resonance Imaging mapping techniques and wide-field retinotopic stimulation were used to verify the presence of pattern motion sensitivity in human area V6. Area V6 is highly selective for coherently moving fields of dots, both at individual and group levels and even with a visual stimulus of standard size. This stimulus is a functional localizer for V6. The wide retinotopic stimuli used here also revealed a retinotopic map in the middle temporal cortex (area MT/V5) surrounded by several polar-angle maps that resemble the mosaic of small areas found around macaque MT/V5. Our results suggest that the MT complex (MT+) may be specialized for the analysis of motion signals, whereas area V6 may be more involved in distinguishing object and self-motion.


Assuntos
Percepção de Movimento/fisiologia , Lobo Occipital/fisiologia , Lobo Parietal/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Mapeamento Encefálico , Discriminação Psicológica/fisiologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Lobo Occipital/anatomia & histologia , Lobo Parietal/anatomia & histologia , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Retina/fisiologia , Córtex Visual/anatomia & histologia , Campos Visuais/fisiologia , Vias Visuais/anatomia & histologia , Vias Visuais/fisiologia , Adulto Jovem
10.
Prog Neurobiol ; 205: 102116, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34217822

RESUMO

The classical view on motor control makes a clear distinction between the role of motor cortex in controlling muscles and parietal cortex in processing movement plans and goals. However, the strong parieto-frontal connections argue against such clear-cut separation of function. Modern dynamical approaches revealed that population activity in motor cortex can be captured by a limited number of patterns, called neural states that are preserved across diverse motor behaviors. Whether such dynamics are also present in parietal cortex is unclear. Here, we studied neural dynamics in the primate parietal cortex during arm movements and found three main states temporally coupled to the planning, execution and target holding epochs. Strikingly, as reported recently in motor cortex, execution was subdivided into distinct, arm acceleration- and deceleration-related, states. These results suggest that dynamics across parieto-frontal areas are highly consistent and hint that parietal population activity largely reflects timing constraints while motor actions unfold.


Assuntos
Braço , Animais , Movimento , Lobo Parietal , Primatas
11.
Eur Rev Med Pharmacol Sci ; 24(2): 956-962, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32017003

RESUMO

OBJECTIVE: Recurrent respiratory papillomatosis (RRP) is characterized by exophytic, benign, and papillary lesions infected by the virus in the epithelium of the upper aerodigestive tract. RRP is caused by persistent infection of the respiratory epithelium by human papillomavirus (HPV) HPV6 and-11. The clinical course of RRP is unpredictable, frequently relapsing, and may be lifelong. The aim of this study is to evaluate the efficacy and safety of the use of intralesional Cidofovir in the treatment of RRP. PATIENTS AND METHODS: We have selected articles on the use of cidofovir as adjuvant therapy in laryngeal papillomatosis. We reviewed 20 reports that enrolled 185 patients with "adult onset recurrent respiratory papillomatosis" (AORRP) and 85 patients with "juvenile onset recurrent respiratory papillomatosis" (JORRP). We evaluated concentration of cidofovir, number of injections, injection interval, therapeutic response, side effects, and progression to dysplasia. RESULTS: The mean concentration of cidofovir was 7.5 mg/ml at injection. The mean number of injections per patient is 6 with 26 days between injections. The percentage of patients with dysplasia after use of cidofovir is 1.48%. The AORRP response to cidofovir is better with a 74% complete response rate, compared to 56.5% of the JORRP. CONCLUSIONS: Intralesion use of cidofovir has a good adjuvant action in RRP increasing the complete remission of the disease. The treatment does not increase the risk of laryngeal dysplasia.


Assuntos
Antivirais/administração & dosagem , Cidofovir/administração & dosagem , Infecções por Papillomavirus/tratamento farmacológico , Infecções por Papillomavirus/fisiopatologia , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/fisiopatologia , Relação Dose-Resposta a Droga , Humanos , Injeções Intralesionais , Infecções por Papillomavirus/diagnóstico , Infecções Respiratórias/diagnóstico
12.
Sci Rep ; 9(1): 936, 2019 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-30700783

RESUMO

Several investigations at a single-cell level demonstrated that the medial posterior parietal area V6A is involved in encoding reaching and grasping actions in different visual conditions. Here, we looked for a "low-dimensional" representation of these encoding processes by studying macaque V6A neurons tested in three different tasks with a dimensionality reduction technique, the demixed principal component analysis (dPCA), which is very suitable for neuroprosthetics readout. We compared neural activity in reaching and grasping tasks by highlighting the portions of population variance involved in the encoding of visual information, target position, wrist orientation and grip type. The weight of visual information and task parameters in the encoding process was dependent on the task. We found that the distribution of variance captured by visual information in the three tasks did not differ significantly among the tasks, whereas the variance captured by target position and grip type parameters were significantly higher with respect to that captured by wrist orientation regardless of the number of conditions considered in each task. These results suggest a different use of relevant information according to the type of planned and executed action. This study shows a simplified picture of encoding that describes how V6A processes relevant information for action planning and execution.


Assuntos
Braço/fisiologia , Força da Mão , Mãos/fisiologia , Neurônios/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Macaca fascicularis , Masculino , Movimento/fisiologia , Neurônios/citologia , Lobo Parietal/citologia
13.
Acta Otorhinolaryngol Ital ; 37(1): 46-50, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28374870

RESUMO

Tracheostomy decannulation has always been considered a procedure with an attendant risk, especially in patients with a reduced upper airway diameter as is commonly observed in the obstructive sleep apnoea (OSA) population. We report on 4 cases where transoral robotic surgery (TORS) helped in the management of long-term cannulated patients. The aims of our paper are: 1. To demonstrate how the otolaryngology team can help identify patients at high risk for decannulation failure; and 2. To demonstrate how TORS may aid in the decannulation process of patients at high risk for failure due to severe tongue base hypertrophy. From our experience, TORS appears to offer an effective option to aid in the decannulation of patients with a severe hypertrophy of the base of tongue and floppy epiglottis.


Assuntos
Remoção de Dispositivo , Procedimentos Cirúrgicos Robóticos/métodos , Traqueostomia , Adulto , Idoso , Cateterismo/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Boca , Medição de Risco
14.
Sci Rep ; 6: 21646, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26876496

RESUMO

Spatial representations in cortical areas involved in reaching movements were traditionally studied in a frontoparallel plane where the two-dimensional target location and the movement direction were the only variables to consider in neural computations. No studies so far have characterized the reference frames for reaching considering both depth and directional signals. Here we recorded from single neurons of the medial posterior parietal area V6A during a reaching task where fixation point and reaching targets were decoupled in direction and depth. We found a prevalent mixed encoding of target position, with eye-centered and spatiotopic representations differently balanced in the same neuron. Depth was stronger in defining the reference frame of eye-centered cells, while direction was stronger in defining that of spatiotopic cells. The predominant presence of various typologies of mixed encoding suggests that depth and direction signals are processed on the basis of flexible coordinate systems to ensure optimal motor response.


Assuntos
Percepção de Profundidade , Neurônios/fisiologia , Lobo Parietal/fisiologia , Potenciais de Ação , Animais , Movimentos Oculares/fisiologia , Fixação Ocular/fisiologia , Macaca fascicularis , Masculino , Modelos Neurológicos
15.
Med. oral patol. oral cir. bucal (Internet) ; Med. oral patol. oral cir. bucal (Ed.impr.);25(2): e283-e290, mar. 2020. graf, tab, ilus
Artigo em Inglês | IBECS (Espanha) | ID: ibc-196258

RESUMO

BACKGROUND: To assess if photobiostimulation (PBS) alleviates pain intensity/duration and swelling after implant surgery. MATERIAL AND METHODS: Sixty subjects (27 male and 33 female, with a mean age of 47,13 8.05 years) were included and randomly assigned to experimental group (implant surgery and photobiostimulation), placebo group (implant surgery and simulated photobiostimulation) and control group (implant surgery only). INCLUSION CRITERIA: subjects older than 20 years, with a healthy oral mucosa and requiring implant surgery. EXCLUSION CRITERIA: pregnancy, history of implant failure, light sensitivity, metabolic deseases, consumption of antibiotics or corticosteroids in the last two weeks, smokers and alcohol drinkers. Patients reported the pain experienced by using a numeric rating scale (NRS) at 2 hours, 6 hours, 12 hours, 24 hours and from day 2 to 7. Swelling score was assessed by linear measurements and type and number of analgesic drugs within each time-point were recorded on a spreadsheet. Data of pain and amount of swelling were compared among the three groups by using the Kruskal-Wallis H Test and post-hoc comparisons tests. RESULTS: Pain in the experimental group was less compared to controls and placebo group, at each time intervals (p < 0.001) as well as the maximum pain score (experimental group: median = 2, interquartile range 2-3; control group: median = 8, interquartile range 3,75-9; placebo group: median = 8, interquartile range 6,25-9). Swelling was almost insignificant in the experimental group (maximum value = 1, interquartile range 0-2,75, at 24 hours) compared with control (maximum value = 6, interquartile range 5-8,75, at 24 hours) and placebo (maximum value = 6, interquartile range 5-8, at 24 hours). Subjects in the experimental group assumed less analgesics compared to both controls and placebo groups. CONCLUSIONS: Photobiostimulation is an effective method to reduce pain intensity/duration and swelling after implant surgery


No disponible


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Implantação Dentária/efeitos adversos , Dor Pós-Operatória/prevenção & controle , Terapia com Luz de Baixa Intensidade/métodos , Fatores de Tempo , Resultado do Tratamento , Análise de Variância , Estatísticas não Paramétricas , Medição da Dor
16.
Eur J Neurosci ; 3(5): 452-461, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-12106184

RESUMO

Extracellular recordings were made in the anterior bank of the parieto-occipital sulcus of two waking monkeys trained to perform fixation tasks in normal illumination or in complete darkness. Of the recorded neurons, 73% (251/343) were responsive to visual stimulation, but their overall organization did not conform to a simple, continuous retinotopic map. Most of the visual neurons showed a high degree of orientation and direction sensitivity, higher than that found in areas V1, V2 and V3A under the same experimental conditions. Whether they had a resolvable receptive field or not, the discharge rate of many neurons in the anterior bank of the parieto-occipital sulcus was influenced by oculomotor activity. The animals were required to execute pursuit or saccadic eye movements in darkness. Saccadic eye movements were found to influence 19% of the neurons tested (29/156); by contrast, pursuit eye movements were without effect (0/64). Saccade responses were direction-tuned and, in several cases, the neuronal discharge started before the onset of eye movement. The animals were also required to gaze, in darkness, at nine different positions on the screen they faced. Of the neurons tested, 59% (102/174) were affected by the direction of gaze. Higher discharge rates were generally observed when the animals looked towards the lower part of the field of view. Given the functional properties of its neurons, its connections with area V3A-where neural signals appropriate for building an objective map of the visual space are present (Galletti and Battaglini, 1989, J. Neurosci., 9, 1112-1125)-and its output to the visuomotor centres involved in the generation of saccades (frontal eye fields and superior colliculus), we infer that the cortex of the anterior bank of the parieto-occipital sulcus might be part of the network involved in the control of gaze in order to locate objects in visual space.

17.
J Comp Neurol ; 402(3): 327-52, 1998 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-9853903

RESUMO

Superior area 6 of the macaque monkey frontal cortex is formed by two cytoarchitectonic areas: F2 and F7. In the present experiment, we studied the input from the superior parietal lobule (SPL) to these areas by injecting retrograde neural tracers into restricted parts of F2 and F7. Additional injections of retrograde tracers were made into the spinal cord to define the origin of corticospinal projections from the SPL. The results are as follows: 1) The part of F2 located around the superior precentral dimple (F2 dimple region) receives its main input from areas PEc and PEip (PE intraparietal, the rostral part of area PEa of Pandya and Seltzer, [1982] J. Comp. Neurol. 204:196-210). Area PEip was defined as that part of area PEa that is the source of corticospinal projections. 2) The ventrorostral part of F2 is the target of strong projections from the medial intraparietal area (area MIP) and from the dorsal part of the anterior wall of the parietooccipital sulcus (area V6A). 3) The ventral and caudal parts of F7 receive their main parietal input from the cytoarchitectonic area PGm of the SPL and from the posterior cingulate cortex. 4) The dorsorostral part of F7, which is also known as the supplementary eye field, is not a target of the SPL, but it receives mostly afferents from the inferior parietal lobule and from the temporal cortex. It is concluded that at least three separate parietofrontal circuits link the superior parietal lobule with the superior area 6. Considering the functional properties of the areas that form these circuits, it is proposed that the PEc/PEip-F2 dimple region circuit is involved in controlling movements on the basis of somatosensory information, which is the traditional role proposed for the whole dorsal premotor cortex. The two remaining circuits appear to be involved in different aspects of visuomotor transformations.


Assuntos
Macaca fascicularis/fisiologia , Macaca nemestrina/fisiologia , Lobo Parietal/fisiologia , Animais , Eletrofisiologia , Histocitoquímica , Macaca fascicularis/anatomia & histologia , Macaca nemestrina/anatomia & histologia , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Lobo Parietal/anatomia & histologia , Especificidade da Espécie
18.
Behav Brain Res ; 76(1-2): 143-54, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8734049

RESUMO

The present review is aimed at analyzing and discussing some of the cortical mechanisms possibly involved in the perception of object motion and object localization in the visual field. A comprehensive approach to these topics would be beyond the scope of this work. The highest priority, therefore, will be given to the cortical machinery involved in these processes, while very little (or nothing at all) will be said on the possible role played by subcortical structures such as the lateral geniculate nucleus and the superior colliculus which, albeit not directly involved in perception, might contribute to it.


Assuntos
Percepção de Movimento/fisiologia , Percepção Espacial/fisiologia , Córtex Visual/fisiologia , Animais , Gatos , Movimentos Oculares/fisiologia , Haplorrinos , Humanos , Analisadores Neurais/fisiologia , Neurônios/classificação , Neurônios/fisiologia , Propriocepção/fisiologia , Córtex Visual/anatomia & histologia , Campos Visuais/fisiologia
19.
Brain Res ; 124(2): 251-61, 1977 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-843947

RESUMO

The influence of ambient illumination on the maintained electrical activity of single neurons of the cat visual cortex was studied by using the closed chamber technique for extracellular recordings. Several levels of light background within the scotopic-mesopic range were explored. Phasic and tonic changes in firing rate were observed following a background change. The former were irregular and unpredictable variations lasting up to 15-20 min. The latter, which usually followed the phasic changes, showed the constant characteristic of being in direct relation to luminance variations for neurons isolated in the striate area and in inverse relation for units recorded from the two non-striate areas of the visual cortex; in all cases, they lasted until a new luminous level was set. Changes in firing rate were not dependent upon either the neuron receptive field organization or the EEG pattern, simultaneously recorded. The background-locked firing rate variations recorded at the visual cortex seem to be the result of a particular cortical distribution of afferent fibers carrying luminance information. Applications to vision research are also suggested.


Assuntos
Potenciais de Ação , Adaptação Ocular , Retina/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais , Gatos , Eletroencefalografia , Luz , Neurônios/fisiologia , Fatores de Tempo , Córtex Visual/citologia
20.
Brain Res ; 260(1): 128-30, 1983 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-6824950

RESUMO

Extracellular recordings were carried out in the primary visual cortex of behaving monkeys. Neurons were activated by moving a visual stimulus on their receptive fields during periods of steady fixation and by moving their receptive fields (smooth pursuit eye movements) on a motionless visual stimulus. Regarding non-oriented cells, they turned out to be activated by the visual stimulation both during steady fixations and smooth pursuit eye movements. Therefore, the non-oriented cells we studied seem not to receive an extraretinal signal related to the slow eye movements.


Assuntos
Movimentos Oculares , Fixação Ocular , Percepção de Movimento/fisiologia , Córtex Visual/citologia , Animais , Potenciais Evocados Visuais , Macaca nemestrina , Neurônios/fisiologia
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